Electric cutter for ceilings, walls, and the like



Feb. 12, 1935. E, HEUBACH 1,990,991

ELECTRIC CUTTER FOR GEIL-INGS, WALLS, AND THE LIKE Filed April 25,- 1934INVENTOR ERNEST HEUBACH -.5' tionJof a device as mentioned-which is:char Yet Patented Feb. 12, 19 35 v +1.;

"Ernest Heubach, New York, N. Y.

movements in an electric cutter-for cracks in ceilingsand walls ofplaster, etc.

:{IIhe invention hasfor an object theconstrucaoterized byits abilityto-absorb dust and small particles produced when cutting .out rthe.plaster of a wall. 1; v ,Still further, the invention proposes thearrangement of a tubular casing open at'the'front the shaft drawnthrough the frontof the casing and discharge through said conduit.

Furthermore, as another object of this invene tion it is proposed toarrange a battle within the front of the casing to coact with the actionof the suction fan in moving air through the conduit.

Still further, it is proposed to provide a thrust bearing for the motorso as to take up the thrust due to operating the cutting tool.

- Another one of the objects of this invention is the arrangement oftelescopic shaft sections composing the front portion of the shaft forsaid 1 tool, and a mechanism for telescopically moving said shaftsections to extend or retract the cutting tool relative to the front ofthe casing.

Furthermore, the mechanism is also proposed for latching the telescopingshafts in various extended positions. i

vThe invention also contemplates an arrangement whereby a grinding toolsuch as a sandpaper disc may be substituted for the cutting tool:

As another object of this invention it is proposed to construct a deviceas mentioned. which is simple and durable and which maybe 'manu facturedand sold at a reasonable cost. I

. For further comprehensionof the .invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawing, and to the appended claims in which thevarious novel features of the invention are more particularly setforth.v "In the accompanying drawing forming a material part of thisdisclosure:---

-'Fig. 1 is a longitudinal sectional view of a device constructedaccording to this invention;

Fig. 2'is a fragmentary view of the front por-.

tion of Fig. 1 but illustrating a different tool substitute. g g. 1

'of substantially hemispherical shape.

.1 Fig. is a fragmentary View of-a portion of Fig. 1 but illustratingvamodification vention. v

' Fig. 4:18 a side elevational view of another type of cutting, tool forthedevice. v

The electric-cutter-for cracks in ceilings, walls;

of .the in eto., comprises .a tubular casing consisting of-a. 1 frontcasing section detachably connected with a rear casingsection 11, saidcasing being provided with'afront open end 12 andalso: being providedwith a partition 13 for dividingit into a front compartment and aclosed-rear compartm'ent. An electric motor14 is arranged with'-. in theclosed rear, compartment of the casing and has its shaft 15 extendingexactly through the center of the casing. Acutting tool 16 is detachablymounted upon the end of theshaft-15. i A hollow conduit 17 connects thefront ofv the casing with the inletvl8 of a-dust bag collector 19. Asuction fan 20 is arranged upon the shaft 15 for drawing through thefront of the casing an discharging "through the conduit 17.

The cutting tool 16 is shown of conical shape and comprises apluralityof'radial blades,.and is formed with a threaded stud 21 at the rear endadapted to engage into a threaded aperture formed in the end of theshaft 15.' The cutting tool 16 in Fig. i is similarly constructed but isA spider construction 22 is mounted within the front end of the casingand has openingsfor the passage of air, and a hub portion 23 equippedwith a bearing 24 for the shaft 16. A baffle plate 25 is arranged withinthe front portion of the casing and acts in conjunction with the suctionfan 20 to direct thedischarge through the conduit 17. More particularly,the suction fan 20 is of the centrifugal The conduit 17 is in the formof a handle by which the device may be supported and manipulated. Therear of the conduit 17 terminates in a portion 28 which is attached uponthe rear closed end'of the casing section 11. The portion 28 is .alsoprovided with a flange 29 which con-' meets with the inlet 18 of thedust bag collector.

A-suitable arrangement is provided so that the inlet 18 may be separatedfrom the flange 29.

' The casing section 11 has areduced shoulder 30 at the front end uponwhich the rear end of the casing sction'lO engages.

other means may be 'provided'for holding these casing sections together.Several bent openings 31 are formed in the casing section 11 to preventoverheating of the motor." A fan 32 is mounted upon the shaft'lfi of themotor so as toproduce.

Frictional means or bearingis arranged toresist the pressureofxthe.

shaft 15 and comprises a bracket 36 attached upon the disc 35 forsupporting an expansion;

spring 3'? carrying a bearing ball 38 at its end engaging against theend of the shaft '33. [1

The operation of the device consists in holding the handle, the conduit1'7, and moving the device along so that the cutter 16 cuts the materialof the plaster in the sides of the crack. The open" end 12 of the casingpreferably should be in intimate contact with the wall or ceiling sothat a large amount-of dust is-draw'n in by the suction fan. This dustis discharged and collected in the dust bag 19.

InFig. 2 another arrangement :of the device has been illustrated inwhich a sandpaper block 40 is shown substituted for the .tool .16. Thissandpaper block is also shown provided with a threaded stud -21 which.threadedly .engages in :the endof theis'haft .15. The device may thusbe used for finishing the plaster surface -.or other similar purposes. a

In Fig. 3 a modified arrangement has beendisclosed in which provision ismade for slightly extending and slightly retracting the cutting tool.With this arrangement .it is possible that first a small out be taken inthe crack of the plaster and then a larger cut and in this manner thefront open end of the casing may always be inintimate contact with the:surface of the wall.

More particularly, the :means mentioned in the previous paragraphcomprises telescopic shaft sections 15 and 15 substituted for the shaft15. The shaft section 15 is integral with the rotor of the motor and hasa square portion extending into a corresponding opening in the section15' to transmit rotations. A flange 41 is fixed :upon the shaft section15 and an expansion spring 42 acts between the partition or spider Y22and the flange 41 for normally urging the shaft section 15 into aretracted position. A pin 43 extends from the side of the :shaft section15 and works in an elongated slot formed in the end of a lever 44 whichis pivotally supported at 45 upon the casing of the device and whichextends through an opening to the exterior. A link 46 connects with theextended end of the lever 44 and connects with a trigger 47. Thistrigger is pivotally mounted .intermediately at 48 upon the conduit 17.The front end of the trigger extends into the vicinity where the indexfinger would be so that it may be readily manipulated.

A rack 49 is pivotally supported at the point 50 upon the spider 22 andis engageable with a tooth 51 projecting from the shaft section 15. Thisrack, in a horizontal position engages the tooth 51 and also abutsagainst a stop 52 projecting from the casing of the device. A link 53 isequipped with a;pin working in a slot in the end of the rack 49 and thelink 53 extends to :the exterior of the casing. A ring 54 is attachedupon the extended endof the link 53. A coaxial spring 55 acts betweenthe casing of the rack 49 to normally urge it into the horizontalposition. The link 53 is composed of two sections including an outersection formed with an elongated slot 56 in which a pin 57 from theinner section engages. The arrangement is such that the link 53 may beextended to a point at which the outer section may be pivoted at rightangles and moved to a position so as to be locked outside of the casing.

Then the rack 49 is held in an inoperativeposi'tiori. In operation therack 49 may be moved to its inoperative position so that the extensionand retraction-of the cutting tool can zbe icontrolled instantly.;by;:moving thestriggerg i'l. If desired, the cutting tool maybelatchedin any of its ex- .tended positions by allowing the rack 49 tomove to thehorizontal position. In other respects the jdevice'functionsas previously described relative "to the-preferred form.

- Having thus .described my invention, what I claim as new, and desireto secure by United States Letters Patent 151-- 1..An-electric cutterfor cracks in ceilings and walls of plaster, etc., comprising a tubularcasing open at the front end and having a partition dividing it intofront and rear compartments, an electric motor in the closed rearcompartment and having its shaft co-axially extending through the fronterid ofthe casing; a cutting tool on the front end of the shaft forcutting \the plaster of i-thecrack, a hollow conduit connecting thefront compartment with the inlet of a dust bag collector, ::and .asuction fan on said shaft for drawing air throughthe front of the casingand discharging through said conduit; 4 Y

2..Anlelectric cutter forcracks in-ceilings and walls of plaster, etc.,comprising-a tubular casing open at the frontend and having a partitiondividing it,.into front and'rear compartments, an electric motor in' theclosed rear compartment and having its shaft coaxially extending throughthe front endof the casing, acutting tool on the front endof the shaftfor cutting the plaster of the :crack, .a hollow conduit connecting thefront compartment with the inlet of a dust bag collector, and a suctionfan on said shaft fordrawing air through the front of the casing anddischarging through said conduit, a baffle plate with a central openingbeing arranged to the front of the suction bag.

3. An electric cutter for cracks in ceilings and walls of plaster, etc.,comprising a tubular casing open at the front end and having a partitiondividing it into front and rear compartments, an electric motor in theclosed rear compartment and having its shaft-coaxially extending throughthe front end of the casing, a cutting tool on the front end of theshaft for cutting the plaster of the'crack, a hollow conduit connectingthe front compartment with the inlet of a dust bag collector, and .asuction fan on said shaft for drawing air through the front of thecasing and discharging through said conduit, a baffle plate with acentral opening being arranged to the front of the suction bag, and saidfan being of the centrifugal type discharging through the ends of theconduit arranged on the peripheryof the casing inthe vicinity of thefan.

4. An electric cutter for cracks inceilings and walls of plaster, etc.,comprising a tubular casing open at the front end and having a partitiondividing it into front and rear compartments, an electric motor in theclosed rear compartment and-having its shaft coaxially extending throughthe front end of the casing, a cutting toolon the frontend of theshaftfor cutting the plaster of the crack; a hollow conduit connectingthe front compartment with the inlet of a dust bag collector, and asuction fan on'said shaft for-drawing air through the front of the:casing' and discharging through said conduit, said rear compartmentbeing formed with several vents.

:5. An .electric cutter for cracks in ceilings and walls of plaster,etc., comprising a tubular casing open at the front end and having apartition dividing it into front and rear compartments, an electricmotor in the closed rear compartment and having its shaft coaxiallyextending through the front end of the casing, a cutting tool on thefront end of the shaft for cutting the plaster of the crack, a hollowconduit connecting the front compartment with the inlet of a dust bagcollector, and a suction fan on said shaft for drawing air through thefront of the casing and discharging through said conduit, said rearcompartment being formed with several vents, and a fan being arrangedupon the motor rotor in said rear compartment.

6. An electric cutter for cracks in ceilings and Walls of plaster, etc.,comprising a tubular casing open at the front end and having a partitiondividing it into front and rear compartments, an electricmotor in theclosed rear compartment and having its shaft coaxially extending throughthe front end of the casing, a cutting tool on the front end of theshaft for cutting the plaster of the crack, a hollow conduit connectingthe front compartment with the inlet of a dust bag collector, and asuction fan on said shaft for drawing air through the front of thecasing and discharging through said conduit, said electric fan beingequipped with a thrust bearing at the rear end.

7. An electric cutter for cracks in ceilings and walls of plaster, etc.,comprising a tubular casing open at the front end and having a partitiondividing it into front and rear compartments, an electric motor in theclosed rear compartment and having its shaft coaxially extending throughthe front end of the casing, a cutting tool on the front end of theshaft for cutting the plaster of 'the crack, a hollow conduit connectingthe front compartment with the inlet of a dust bag collector, a suctionfan on said shaft for drawing air through the front of the casing anddischarging through said conduit, the rotor of said elec tric fan havinga bearing, said bearing including 'a resilient thrust mechanism.

8. An electric cutter for cracks in ceilings and walls of plaster, etc.,comprising a tubular casing open at the front end and having a partitiondividing it into front and rear compartments, an electric motor in theclosed rear compartment and having its shaft coaxially extending throughthe front end of the casing, a grind-ing disc on the front end of theshaft for cutting the plaster of the crack, a hollow conduit connectingthe front compartment with the inlet of a dust bag collector, and asuction fan on said shaft for drawing air through the front of thecasing and discharging through said conduit.

9. An electric cutter for cracks in ceilings and walls of plaster, etc.,comprising a tubular casing open at the front end and having a partitiondividing it into front and rear compartments, an electric motor in theclosed rear compartment and having its shaft coaxially extending throughthe front end of the casing, a cutting tool on the front end of theshaft for cutting the plaster of the crack, a hollow conduit connectingthe front compartment with the inlet of a dust bag collector, a suctionfan on said shaft for drawing air through the front of the casing anddischarging through said conduit, and. the tool carrying portion of saidshaft comprising telescopic sections arranged for unitary rotation andone section being movable relative to the other means for fixing saidshaft sections in various positions, and means for controlling extensionand contraction of said shaft sections.

10. An electric cutter for cracks in ceilings and walls of plaster,etc., comprising a tubular casing open at the front end and having apartition dividing it into front and rear compartments, an electricmotor in the closed rear compartment and having its shaft coaxiallyextending through the front end of the casing, a cutting tool on thefront end of the shaft for cutting the plaster of the crack, a hollowconduit connecting the front compartment with the inlet of a dust bagcollector, a suction fan on said shaft for drawing air through the frontof the casing and discharging through said conduit, and the toolcarrying portion of said shaft comprising telescopic sections arrangedfor unitary rotation and one section being movable relative to the othermeans for fixing said shaft sections in various positions, and means forcontrolling extension and contraction of said shaft sections, said meansfor fixing the shaft sections including a rack engageable with a toothprojecting from the relatively movable of said sections.

11. An electric cutter for cracks in ceilings and walls of plaster,etc., comprising a tubular casing open at the front end and having apartition dividing it into front and rear compartments, an electricmotor in the closed rear compartment and having its shaft coaxiallyextending through the front end of the casing, a cutting tool on thefront end of the shaft for cutting the plaster of the crack, a hollowconduit connecting the front compartment with the inlet of a dust bagcollector, a suction fan on said shaft for drawing air through the frontof the casing and discharging through said conduit, and the toolcarrying portion of said shaft comprising telescopic sections arrangedfor unitary rotation and one sec tion being movable relative to theother means for fixing said shaft sections in various positions, andmeans for controlling extension and contraction of said shaft sections,including a trigger in the vicinity of said hollow conduit which latterelement comprises a handle.

12. An electric cutter for cracks in ceilings and walls of plaster,etc., comprising a tubular casing open at the front end and having apartition dividing it into front and rear compartments, an electricmotor in the closed rear compartment and having its shaft coaxiallyextending through the front end of the casing, a cutting tool on thefront end of the shaft for cutting the plaster of the crack, a hollowconduit connecting the front compartment with the inlet of a dust bagcollector, a suction fan on said shaft for drawing air through the frontof the casing and discharging through said conduit, and the toolcarrying portion of said shaft comprising telescopic sections arrangedfor unitary rotation and one section being movable relative to the othermeans for fixing said shaft sections in various positions, and means forcontrolling extension and contraction of said shaft sections, includinga trigger in the vicinity of said hollow conduit which latter elementcomprises a handle, and resilient means for urging the movable of thetelescopic shaft sections in one direction.

ERNEST HEUBACH.

